Traveling-wire electroerosion machines, frequently abreviated TW-EDM machines (in the case of electric discharge machining), are machine tools in which an elongated electrode is displaced substantially continuously along a generally rectilinear path along the length of the machining stretch of the electrode between a pair of wire guides from an electrode supply system to an electrode takeup system.
The term "electroerosion" is used generically to describe electrical machining using such an electrode and a machining liquid which is introduced into the region at which the electrode is juxtaposed with the workpiece, inter alia to sweep the machining zone free from machining detritus, i.e. material removed from the conductive workpiece.
In EDM, the machine liquid is generally a dielectric e.g. wire of low conductivity and the machining is effected by impressing discharge electrical pulses across the electrode and the workpiece so that discharges develop in the gap between the workpiece and the electrode to remove material at least preferentially from the workpiece.
There are other types of electroerosion which utilize, for example, electrochemical solubilization of workpiece material (ECM) or a combination of electrochemical and discharge machining (ECDM) in which the liquid can have a more conductive character.
In practically all cases, the electrical energy utilized in the machining process is supplied to the machining zone in the form of discrete electrical pulses.
The term "wire" is used herein to describe the machining electrode and should also be understood to encompass elongated members generally and thus wires of various cross-sectional configurations as well as tapes, ribbons or the like. The electrode, of course, should be conductive and the thickness of the electrode should be between 0.05 mm and 0.5 mm.
In the published Europatent application No. 0 142 034, corresponding to European patent application No. 84 11 22 10.4 filed Oct. 11, 1984 and published May 22, 1985, there is described a traveling-wire electro-erosion machine with double-floating nozzle assemblies.
The floating-nozzle assembly can serve to deliver the machining liquid to the machining zone and can be traversed by the machining electrode or wire and in that system, the flow of the machining liquid is axial, i.e. parallel to the axial travel of the tool electrode.
The floating fluid-delivery nozzles of that system are axially movable so that, for example, they may be urged toward engagement with the workpiece to constrict the zone at which the liquid may flow away from the face with which this nozzle is juxtaposed.